Silicon wafers

Which impurity is typically added to the melt to make p-type silicon crystals by the CZ method?

  1. APhosphorus (P)
  2. BArsenic (As)
  3. CBoron (B)
Show answer and explanation

Answer: C. Boron (B)

Boron, a group III element, is added to make p-type silicon. For n-type, group V elements such as phosphorus, arsenic and antimony are used. The crystal's resistivity is set by the amount of dopant added.

Practice this topic Back to topic

More Silicon wafers questions

  1. When a doped crystal is pulled by the CZ method, the dopant concentration tends to be higher toward the bottom of the crystal (later in the pull). Why?
  2. Which correctly describes 450 mm wafers, developed as the next diameter after 300 mm?
  3. What is the purpose of using bulk microdefects (BMDs), formed by oxygen precipitation inside CZ wafers?
  4. Heat treatment of a wafer diffuses oxygen out from near the surface, creating a low-defect layer at the surface where devices are made. What is this layer called?
  5. What is the purpose of the laser mark (ID mark) inscribed on the front or back of a wafer?